What is heart reentry?

Reentry, due to a circuit within the myocardium, occurs when a propagating impulse fails to die out after normal activation of the heart and persists as a result of continuous activity around the circuit to re-excite the heart after the refractory period has ended; it is the electrophysiologic mechanism responsible for …

What is reentry conduction?

As described elsewhere, conduction blocks can cause bradycardia; however, they can also cause tachycardia. This occurs when impaired conduction leads to a phenomenon termed “reentry.” In fact, this mechanism may account for most tachyarrhythmias found in patients.

What is re entry arrhythmia?

A reentry arrhythmia is a self-sustaining cardiac rhythm abnormality in which the action potential propagates in a manner analogous to a closed-loop circuit. It is a disorder of impulse conduction and is discrete from disorders of impulse generation such as automaticity or triggered activity.

Is AFIB a re entry?

AF can be maintained by reentry and/or rapid focal ectopic firing (Figure 1). 2 The mechanism maintaining AF is often called the driver.

How does reentry occur?

What triggered activity?

Triggered activity is a term used to describe impulse initiation in cardiac fibers that is dependent on afterdepolarizations 2. Afterdepolarizations are oscillations in membrane potential that follow the upstroke of an action potential. Two kinds of afterdepolarizations may cause triggered activity.

What causes a reentry circuit?

Is WPW regular or irregular?

Abnormal electrical system in WPW The most common arrhythmia associated with WPW syndrome is called paroxysmal supraventricular tachycardia. Some people with WPW syndrome have a type of irregular heartbeat known as atrial fibrillation.

What is functional reentry?

In functional reentry, the reentrant impulse propagates around an area with a functional (i.e. unassociated with an anatomical barrier) conduction block. In the leading circle concept, during wave rotation, the wavefront impinges on its refractory tail.

What causes re-entry?

Is AVNRT micro reentry?

Pathophysiology. AVNRT and AVRT are electrical aberrancies that occur mainly as a result of reentry. Less commonly, increased automaticity or triggered activity can be the mechanism and usually results in a narrow complex tachycardia.

Is af an arrhythmia?

The main types of arrhythmia are: atrial fibrillation (AF) – this is the most common type, where the heart beats irregularly and faster than normal. supraventricular tachycardia – episodes of abnormally fast heart rate at rest. bradycardia – the heart beats more slowly than normal.